Cable control mechanism



R. M. SMITH CABLE CONTROL MECHANISM Oct. 25, 1949.

Filed June 4, 1948 2 Shee'ts-Sheet 1 INVENTOR.

ATTORNEE.

Oct. 25, 1949. R. M. SMITH CABLE CONTROL MECHANISM 2 Sheets-Sheet 2Filed Tune 4, 1948 .Uil'l'lllllllli a v \N mv 1&5.

INVENTOR. figger l. Jmi/A m lh ATTORNEY Patented Oct. 25, 1949 CABLECONTROL MECHANISM Roger M. Smith, Goodyear, Aria, assignor toCaterpillar Tractor 00., Peoria, 111., a corporation of CaliforniaApplication June 4, 1948, Serial No. 31,162

5 Claims.

This invention relates to cable control mechanism in general and moreparticularly to a cable control mechanism which permits the selectiveoperation of two or more cable controlled implements, connected intandem, from a single power actuated cable winding drum.

There are many instances where it is desirable to employ a single poweractuated cable winding drum for selectively actuating two or more cablecontrolled implements which are connected in tandem. However, forpurposes of illustration, the present invention will be described byreference to a specific mechanism such as a cable control device carriedby a tractor which serves as the draft vehicle for a pair of cablecontrolled earth moving scrapers connected in tandem. Parts of thescrapers are under the control of cables extending to a cable controlunit carried by the tractor. The cable control unit is powered forrotation from the tractor engine and is controlled by the tractoroperator. It is to be understood however that this invention isapplicable to the control of many other types of devices and that thisdisclosure of a specific mechanism is made for the purpose ofillustrating the invention by reference to one specific form which itmay assume.

Some cable control units of this type now used for controlling themovable elements of a pair of cable controlled earth moving scrapersconnected in tandem require the use of four power actuated cable windingdrums; two of which are required for controlling each scraper. Theresulting bulk and duplication of controls makes this type of cablecontrol impractical, as well as tending to limit the number of cablcontrolled scrapers which can be connected in tandem due to spacerequirements.

It is therefore an object of this invention to provide a simpleinexpensive cable control system which permits the selective operationof any number of cable controlled elements connected in tandem.

Further and more specific objects and advantages of this invention aremade apparent in the following specification wherein reference is madeto the accompanying drawings.

In the drawings:

Fig. 1 is a view in side elevation of a tractor andscraper combinationwherein a tractor, partially shown, is drawing and carrying cablecontrols for a first scraper and a second scraper, also partially shown,and

Fig. 2 is a schematic view of the cable control mechanism of the presentinvention.

Referring to the drawings in detail, Fig. 1 illustrates a tractor I0employed as the draft vehicle for a pair of earth moving scrapers II andI2 connected in tandem. Though the scrapers do not in themselves form apart of the present invention, their principle elements will be brieflydescribed in order to facilitate an understanding of the controls ofthis invention. Each of the scrapers comprises ground engaging wheels|3, a draft frame I4, and a scraper bowl Hi. The scraper bowl I6 ispivotally supported about the axis of the rear wheels and is adapted tobe lowered into ground contact for the collection of earth. The forwardend of the bowl is adapted to be opened or closed by an apron ll,pivotally supported by a pair of pins, one of which is illustrated at I8as extending from the side of the scraper bowl. The rear of the scraperbowl is closed by an ejector l9 which is adapted to be moved forwardlywith respect to the scraper bowl to discharge the material collectedtherein. The apron, ejector and bowl of th front scraper II arecontrolled by a pair of cables 2| and 22 extending from the scraper to aconventional double drum cable control unit 23 carried on the rear ofthe tractor Ill. The apron, ejector and bowl of the rear scraper I2 arecontrolled by a pair of cables 24 and 25 extending forwardly from thescraper to a pair of cable winding motors 21 and 28, only one of whichis shown in Fig. 1, and which are carried on suitable brackets 29rigidly secured to the rear of the scraper bowl Hi. The cable windingmotors 21 and 28 are actuated by the cables 2| and 22 respectivel in a.manner presently to be decribed. It is with the apparatus forselectively controlling the movable elements of the two scrapers fromthe double drum cable control unit 23 carried by the tractor that thisinvention is concerned.

Th manner in which the cable control mechanism functions isschematically illustrated in Fig. 2 of the drawings. In this figure theelements of the rear scraper I 2, which corresponds to identicalelements of the front scraper I l, are identified by the same referencecharacters primed. In Fig. 2, the cable control unit 23 is illustratedas comprising a pair of cable winding drums 3| and 32 which are poweredfor rotation from the tractor In by means of a conventional powertakeoff (not shown) and controlled by the tractor operator throughconventional controls for winding in or paying out the cables 2| and 22associated therewith. The cable 2| extends from the cable winding drum3| around a pair of guide sheaves 33, supported in the draft frame I4 ofthe 3 scraper H, to a nest of sheaves 84 retained in a sliding sheaveblock 35 and thence to a nest of sheaves 36 retained in the draft frameI 4. The sheave block 35 is secured to a cable 31 which passes aroundsupporting sheaves 38 retained in the draft frame l4 and is anchored atits opposite end to the movable apron l1. Thus, by takingin on the cable2| with the drum 3|,-the sliding sheave block 35 is drawn toward thestationary sheaves 36, thus raising the apron L'Lto its open position inpreparation for loading or unloading operations. Suitable stops (noshown) are provided to limit this movement.

From the sheave nest 36, the cable 2| passes over guide sheaves 39 and48 to a group of sheaves 4| associated with the sliding ejector 1 I9 anda group 42 supported from the scraper bowl I6. The end of the cable iswound upon and anchored to the cable winding motor 28. Resilient meanssuch as springs 43 is disposed between the ejector l9 and the bowl frame16 to return the ejector to the normal load carrying position,illustrated, after it has been advanced to eject the material carried bythe bowl. Ad-

vancing of the ejector is accomplished by continued taking in on thecable 2| after the apron II has reached its fully opened position, thesprings 43 also serve to prevent movement of the ejector forwardly untilthe apron has been completely opened.

The cable winding motor 28 comprises a pair of cable drums 44 and 45,rotatable together about a common shaft 46. The shaft 46 is supported insuitable bearings 41 disposed within the brackets 29 extending from therear of the scraper bowl. The cable 2| associated with the cable windingdrum 3| is anchored to the drum 44 while the drum 45 carries the cable24 associated with apron and ejector I9 of the rear scraper 2. The cable24 is anchored to the bowl frame l6 of the rear scraper as is indicatedat 41'. The arrangement is such that rotation of the drum 3| may imparta like rotation to the drums 44 and 45 of cable winding motor 28 throughthe cable 2|. Rotation of the drum 45 results in the cable 24 associatedtherewith actuating the apron and ejector of the rear scraper |2 in thesame manner as was described in connection with the scraper The cable 22extends from the cable winding drum 32 around a pair of guide sheaves 48supported in the draft frame l4 and thence to a block of sheaves 49retained in a stationary sheave block 50 supported from the draft frame14. From the sheaves 49, the cable extends downwardly to a block ofsheaves carried in a movable sheave block 52 associated with the frontend of the scraper bowl l6. Thus when the cable 22 is paid out from thedrum 32, the scraper bowl is lowered into ground contact to permitfilling of the bowl. At the completion of the loading operation, thebowl is raised by taking in on the cable 22 thus drawing the sheaveblock 52 toward the sheave block 50. From the sheaves 49, the cable 22extends around a guide sheave 54 carried by the draft frame and thenceto the cable winding motor 27. I

The cable winding motor 21 is identical in construction with the cablewinding motor 28 previously described and comprises a pair of cabledrums 55 and 56 connected for rotation together about a common shaft.The cable 22 is anchored to the cable winding drum 55 and the cable 25is anchored to the cable winding drum 56. The cable 25 extends from thedrum 56 around guide sheave 48' to sheaves 49'. From the sheaves 48' thecable extends to the sheaves 5| associated with the bowl l6 of the rearscraper and from there is returned to the stationary sheave block 58where it is anchored. Rotation of.the drum 32 may impart like rotationto the drums and 56 by means of the cable 22. Rotation of the drum 56results'in the cable '25 associated therewith actuating the bowl l6 ofthe rear scraper in the same manner as described in connection with thefront scraper.

Brake shoes 58 are associated one with a flange of each of the cablewinding motors 21 and 28 and serve to prevent rotation of the cablewinding. motors thereby ermitting the front scraper II to be actuatedindependently of the rear scraper |2 by the manipulation of the cables2| and 22. Each of the brake shoes 58 is carried on the extending rod ofa piston 59 disposed within a power cylinder 60. Engagement of the brakeis effected by directing fluid under pressure to the cylinder in amanner presently to be described.

I A spring 6| is disposed in each of the power cylinders 58 and servesto return the brake shoes to the disengaged position.

In order to render the front scraper inoperative. thereby permitting therear scraper to be actuated independently of the front scraper, a numberof latching devices are associated with the movable elements of thefront scraper. Movement of the apron I1 is prevented by a latchingmechanism comprising a lever 62 pivotally supported by a bracket 63extending from the draft frame 14. One end Of the lever is associatedwith a power cylinder a while the opposite end is urged into latchingengagement with the sliding sheave block 35 by the spring loaded piston59a disposed within the power cylinder. The latch is normally engageduntil fluid underpressure is directed to the power cylinder 60a. At thistime, the lever 62 is moved out of latching engagement with the sheaveblock 35 permitting the apron to beopened.

Movement of the ejector I9 is prevented by a similar latching lever 66,pivotally supported by a bracket 61a rigidly secured to the bowl framel6. One end of the latch 66 is associated with a power cylinder 68b andis normally urged into its engaged position by a spring loaded pistontherein. Disengagement is effected by directing fluid under pressure tothe power cylinder at which time the ejector is free to be movedforwardly to unload the scraper bowl. Because the ejector isoccasionally prevented from returning to its fully retracted posit on bythe springs 43.

' due to material becoming lodged in the carriage,

spaced notches 61 and 88 are provided in the lever 66 to insure that alatch part 69 associated with the sliding ejector will be received inone of the notches thereby preventing the ejector from being movedforwardly.

Movement of the bowl i6 is prevented by a similar latching device 16associated with the movable sheave block 52 and which is pivotallysupported by a bracket 12 rigidly secured to the sheaveblock 50. Thelatch 10 is associated with a power cylinder 68c and is actuated in thesame manner as those previously described.

Fluid under pressure is supplied to each of the power cylinders 60, 68a,68b and 680 through a common conduit 13 from a suitable reservoir I4carried on the back of the tractor III. A conventional two positionvalve 15 is located within easy reach of the tractor operator and servesto either direct fluid through the conduit 13 or to release the pressurein the conduit.

With the cable control mechanism herein described, it is possibleselectively to actuate the two scrapers in any desired sequence.However, for purposes of illustration, only one loading and unloadingcycle will be described, as it will be apparent how other sequences canbe obtained. In order to prevent jack-knifing of the rear scraper when apusher vehicle is used to augment the power of the draft vehicle whileloading, it is usually desirable to load the rear scraper first. This isaccomplished by moving the valve 15 to a position wherein any fluidpressure in the conduit i3 is relieved. At this time, the latches 62, 66and will be urged into latching engagement with the sheave block 35,ejector I. and sheave block 52 respectively. At the same time, brakeshoes 58 associated with the cable winding motors 21 and 28 will bemoved to a disengaged position permittin free rotation of the motors. Atthis time, taking in one the cable 2| by the cable winding drum 1|actuates the cable winding motor 28 to take in on the cable 24controlling the rear scraper. Taking in on the cable 24 results in theapron l1 being opened by drawing the sheave block 35' toward the sheaves36'. The bowl I6 is then lowered into ground contact by paying out onthe cable 22 from the cable winding drum 32. As the sheave block 52associated with the bowl N5 of the front scraper is held againstmovement by the latch 18, a like motion is transmitted to the cable 25associated with the cable winding motor 21. Paying out on the cable 25permits the bowl IE to be lowered into round contact for loading. Afterthe scraper bowl is loaded, it is returned to a carrying position bytakin in on the cable 25, drawing the sheave block 52' upwardly. At thesame time, the apron Il may be closed by its own weight by paying out onthe cable 24 from the cable winding motor 28.

Loading of the front scraper II is accomlished by moving the valve to aposition wherein pressure is directed to each of the power cylinders 6060a, 60b and 600, disengaging latches 62, 66 and 10 associated with thesheave block 35, ejector l8 and sheave block 52 respectively andsimultaneously moving the brake shoes 58 into frictional engagement withthe cable winding motors 21 and 28. At this time, the cable windinmotors serve as fixed anchors for the cables 2| and 22 thus permittingthe apron I! to be opened by taking in on the cable 2|. In a similarmanner, the bowl I6 is lowered into ground contact by paying out on thecable 22. At the completion of the loading, the bowl is raised by takingin on cable 22 and the apron i1 is closed by paying out on the cable 2|.

After both of the scrapers have been loaded, they may be transported tothe fill or dump, where again the sequence of operation is optional.However, to permit a continuous earth fill to be laid down, it has beenfound desirable to unload the front scraper first. This is accomplishedby moving the valve 15 to a position wherein the fluid is directed underpressure to the power cylinders 60, 60a, 60b and 600. At this time, thecable winding motors will be prevented from rotating by the brakes 58thus serving as fixed anchors for the cables 2| and 22. Simultaneouslythe latches 62, 66 and 10 will be moved out of engagement with thesheave block 35, ejector l9 and movable sheave block 52, respectively,permitting them to be actuated by'the cables 2| and 22. The apron I1 isopened by taking in on the cable 2|, thus drawing the sliding sheaveblock 35 toward the sheaves 36 until the sheave block comes againstsuitable stops (not shown). Continued taking in on the cable 2| causesthe sheave nest ll carried by the ejector I8 to be drawn forwardlytoward the sheave nest 42, thus moving the ejector forwardly to displacethe material deposited in the scraper bowl. The depth of the fill may becontrolled by lowering the bowl to the desired height above the surfaceof the fill by Pay ng out on the cable 22. After the front scraper IIhas been unloaded, the bowl I6 is returned to its carrying position bytaking in on the cable 22. The apron l1 and ejector l9 are returned tothe carrying position by paying out on the cable 2|. The ejector isretracted by the springs 43 while the apron is lowered by its ownweight.

When it is desired to unload the rear scraper, the valve 15 is moved toa position wherein the pressure in the conduit is relieved thus lockingthe movable elements of the front scraper in the carrying position andsimultaneously releasing the brakes 58 associated with the cable windingmotors 21 and 28. At this time, the cable Winding motors 21 and 28 areactuated by manipulation of the cables 2| and 22, thus permitting therear scraper to be unloaded in the same manner as the unloading of thefront scraper ll just described.

Thus the system permits the selective operation of two cable controlledscrapers connected in tandem. However, it should be understood, that byaddition of suitable cable winding motors, additional air circuits, andlatching devices, that any number of cable actuated devices may beconnected in tandem and controlled from the conventional double drumcable control unit 23 carried by the tractor.

I claim:

1. In combination with a tractor and two cable controlled implementsdrawn thereby in tandem, a cable controlled drum on the tractor, a firstcable between said drum and controlled parts of the first implement, asecond cable control drum on the first implement, a second cable betweensaid second drum and controlled parts of the second implement, and meansoperable by the first cable for actuating the second cable control drum.

2. In combination with a tractor and two cable controlled implementsdrawn thereby in tandem, a cable control drum on the tractor, a firstcable between said drum and controlled parts of the first implement, asecond cable control drum on the first implement, a second cable betweensaid second drum and controlled parts of the second implement, a cablemotor drum associated with the second control drum, said first cablebeing anchored and wound upon said motor drum whereby the operation ofthe second control drum is controlled by the control drum on thetractor.

3. In combination with a tractor and two cable controlled implementsdrawn thereby in tandem, a cable control drum on the tractor, a firstcable between said drum and controlled parts of the first implement, asecond cable control drum on the first implement, a second cable betweensaid second drum and controlled parts of the second implement, a cablemotor drum associated with the second control drum, said first cablebeing anchored and wound upon said motor drum whereby the operation ofthe second control drum is controlled by the control drum on the 7tractor and means to lock the motor drum against rotation.

4. In combination with a tractor and two cable controlled implementsdrawn thereby in tandem, a cable control drum on the tractor, a firstcable between said drum and controlled parts of the first implement, asecond cable control drum on the first implement, a second cable betweensaid second drum'and controlled parts of the second implement, a cablemotor drum associated with the second control drum, said first cablebeing anchored and wound upon said motor drum whereby the operation ofthe second control drum is controlled by the control drum on the tractorand means to lock the controlled parts of the first implement againstoperation by the cable.

5. In combination with a tractor and two cable controlled implementsdrawn thereby in tandem,

' motor drum and release the controlled parts of the first implement foroperation by the cable or to lock said parts and release the motor drum.

ROGER M. SMITH.

No references cited.

